Infection Control Resource Vol. 4 No.2 Prevention Strateg ies for IC Practitioners and Professional Nurses In this issue ntravascular catheters are indispensable in modern-day medical practice. Although these Flushing vascular Itypes of catheters provide necessary vascular access, they can put patients at risk for local and ng Educ ui at systemic infectious complications, including local access catheters: n io ti n site infection, catheter-related bloodstream infections n o (CRBSI), septic thrombophlebitis, endocarditis, and C other metastatic infections. CRBSI is the most life Risks for infection threatening of all healthcare-acquired infections and accounts for significant medical costs, estimated at CECE nd Nurses transmission ontrol Professionals A ion C approximately $2.3-billion annually. The introduction For Infect of microorganisms (and biofilm) during insertion and GE 7 use of vascular catheters is ubiquitous. Effective skin by Lynn Hadaway, RN, C, MEd, CRNI SEE PA antiseptics and application techniques remove most but not all organisms. t has long been accepted that the process Catheter-flushing procedures that result in a sudden onset of fever and chills could be causing the release of flushing vascular access catheters is a of cell clusters from biofilm. Catheter flushing is primary method for maintaining catheter Approximately 87% of much more than injecting some fluid through the patency, although there is very little clini- catheter lumen. Clinical outcomes depend upon the Ical research on the practice. Ideally, the catheter bloodstream infections entire system working together. In her article, Ms. should flush freely without offering any resis- Hadaway discusses infection prevention techniques, are associated with the including proper catheter flushing techniques with tance to the fluid flow. All vascular access devices single-use flushing containers, adequate cleaning of should yield positive blood return when aspi- the needleless surface before each connection, and rated and are considered to be non-functioning presence of some type of careful attention to hand hygiene. when blood return cannot be obtained. intravascular device. VISIT US ONLINE Catheter-related bloodstream infections Infection Control Resource (CRBSI) take a very large toll on clinical and is now online at financial resources in U.S. healthcare. Ap- infusate-related bloodstream infections. The www.infectioncontrolresource.org proximately 87% of bloodstream infections You can now get your FREE CE imemdiately 100,000 Lives Campaign from the Institute for by taking the test online at are associated with the presence of some type Healthcare Improvement, the National Patient www.saxetesting.com of intravascular device.1 CRBSI is the most Safety Goals from the Joint Commission for life-threatening of all healthcare-acquired in- Accreditation of Healthcare Organizations, the Advisory Board fections and accounts for significant medical Committee to Reduce Infection Deaths, the Gwen Beiningen, RN, MS, CIC costs, with total costs estimated as high as $2.3- SAVE That Line! campaign from the Association Infection Control Coordinator billion annually.2 for Vascular Access, and mandates from many Sioux Valley Hospitals & Health Systems Sioux Falls, SD The connection between bloodstream in- state legislatures for mandatory public report- Gail Bennett, RN, MSN, CIC fections and flushing procedures is becoming ing of healthcare-acquired infections are actively Associate Executive Director, a serious area of concern. The technology of promoting attention to this problem among ICP Associates, Rome, GA vascular catheters, pieces added on to the cath- hospital administrators, all levels of healthcare Nancy Bjerke, RN, MPH, CIC Infection Control Associates eter, flush-solution containers, syringe design, workers, and patients and their families. San Antonio, TX and techniques being used must work together To understand how flushing procedures af- Barbara DeBaun, RN, MSN, CIC effectively as a system. Without a systems ap- fect the risk of bloodstream infections we must Director, Infection Control California Pacific Medical Center, San Francisco, CA proach, you will find that changing one piece first explore the major cause of such infections: Elaine Flanagan, BSN, MSA, CIC may not alter your problems with catheter pa- biofilm. Manager Epidemiology tency, and the risk of infections associated with Detroit Medical Center, Detroit, MI flushing procedures will be greater. Catheters and biofilm Susan Slavish, RN, BSN, MPH, CIC Infection Control, Queen’s Medical Center Zero tolerance for healthcare-acquired in- The introduction of microorganisms during Honolulu, HI fections is now the goal, with several national insertion and use of vascular catheters is ubiq- Barbara Soule, RN, MPH, CIC initiatives focused on reducing or eliminat- uitous. As the catheter passes through the skin Consultant, Joint Commission Resources Oakbrooke, IL ing these infections, including catheter- and during insertion, it is exposed to organisms in ResourInfectionce Control the deep layers of the epidermis. About 80% mg of EDTA in 1 mL distilled water. Begin- of resident organisms reside in the top five ning on day 3, catheters in all groups were layers of the epidermis, and the remaining According to the flushed once every 24 hours with the respec- 20% live in biofilm in deep epidermal layers, tive solutions for 5 days. Quantitative blood sebaceous glands, and hair follicles.1 Effec- Infusion Nursing cultures taken from all 18 rabbits on day 3 tive skin antiseptics and application tech- showed S epidermidis. For those undergo- niques remove most but not all organisms, Standards of Practice, ing vancomycin-heparin flushes, 3 out of 5 allowing some to attach to the catheter on showed complete resolution of bacteremia by insertion. In addition, as the catheter hub is there are two purposes day 7; those undergoing minocycline-EDTA used for medication administration, flush- flushes had 100% resolution of the bactere- ing, tubing and cap changes, and blood sam- for flushing a catheter: mia by day 7. pling, other organisms enter and cling to the In-vitro tests by Shah et al.7 inoculated catheter’s internal wall. Catheters that have to maintain catheter catheters with broths growing S aureus, S been used for a few days have more biofilm epidermidis, Pseudomonas aeruginosa, En- on the external wall, while those indwelling patency and to prevent terococcus faecalis, and C albicans, and then for longer periods have more biofilm on the treated them with either a heparin flush of internal wall.1 contact between 5000 U/mL or a taurolidine (1.35% [wt/ When organisms simply touch the cath- vol]) and citrate (2.61% [wt/vol]) solution eter surface, adhesive materials are produced incompatible fluids and flush. The inoculated organisms grew in the that firmly attach them to the catheter wall. heparin-treated catheters while the catheters Once the catheter enters the bloodstream, a medications. treated with taurolidine citrate did not sup- conditioning process begins with proteins port growth of these organisms. also attaching to the catheter surface, fol- Raad et al.8 performed an in-vitro study of lowed by platelets and white blood cells. duction methods and were then correlated to catheter segments plus 54 colonized catheter Within five minutes, the amount of attached the clinical findings. The presence of central tips removed from patients. They also dem- proteins is about equal to the amount in the venous catheters and infusion of parenteral onstrated that heparin can support microbial circulating blood. The normal coagulation nutrition were the clinical factors associated growth in fresh and mature biofilm. process causes the development of a fibrin- with laboratory-developed biofilm. A recent in-vitro study by Shanks et al.9 ous layer on the catheter that is commonly Many studies have shown heparin to sup- examined the mechanisms by which heparin a depth of 1 millimeter within 24 hours of port the growth of organisms both in solu- stimulates the growth of S aureus biofilm. catheter insertion.1 tion and in biofilm. For example, Root et al.5 The findings suggested that heparin does not After attachment to the catheter’s inter- removed a tunneled central venous catheter, increase the attachment of organisms to the nal and external surfaces, organisms grow growing Staphylococcus epidermidis, from a catheter surface, but it does promote cell-cell and multiply to form cell clusters or mush- septic bone-marrow transplant patient and interactions, causing growth of biofilm. room-shaped colonies while also produc- subjected the catheter to numerous labora- ing an exopolymer substance or glycocalyx, tory tests to determine what solution would Catheter-flushing protocols a self-protecting slime. The biofilm surface inhibit the organism’s growth. Catheter seg- Cells embedded in biofilm are known is uneven and is composed of about 10% to ments were incubated in four separate solu- as sessile, while free-floating cells are called 25% organism cells, with the remaining 75% tions: disodium ethylenediaminetetraacetic planktonic cells. Cells, individually or in to 90% being the slime.1 The biofilm con- acid (EDTA) 20 mg/mL, heparin 10 U/mL, clumps or clusters, break off from biofilm tains channels that allow essential nutrients vancomycin 6.7 µg/mL, and a combina- and become planktonic. This mechanism is and oxygen to reach the cells within and the tion of those same doses of vancomycin thought to be the most important